In recent years, a three-dimensionally stacked semiconductor memory device capable of increasing its storage capacity while suppressing an increase in bit cost has been proposed. Such a three-dimensionally stacked semiconductor memory device includes a stacked body in which electrode layers and inter-electrode insulating layers are alternately stacked. Conventionally, after a hole is formed in the stacked body, a portion of the electrode layer exposed in an inner surface of the hole is sometimes oxidized. When the electrode layer with a low resistance is oxidized, the resistance of the electrode layer is increased, constituting a factor in deterioration of charge retention characteristics or memory characteristics such as erasing/writing characteristics.